A076513 Numbers k such that 2 + 2^k + 3^k is prime.

1, 3, 5, 65, 119, 213, 1209, 2469, 2669, 3939, 11219

Offset: 1

Author

Zak Seidov, Oct 17 2002

Keywords

• nonn
• more

Comments

119, 213, 1209 and 2469 proved prime by Primo v1.2.1. - Robert G. Wilson v Oct 17 2002

a(12) > 10^5. - Giovanni Resta, Mar 19 2014

Crossrefs

Cf. A075996.

Programs

Mathematica

Do[ If[ PrimeQ[2 + 2^n + 3^n], Print[n]], {n, 1, 4000, 2}]
Select[Range[10000], PrimeQ[2 + 2^# + 3^#] &] (* _Vincenzo Librandi: Oct 05 2012 *)

PARI

is(n)=ispseudoprime(2+2^n+3^n) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

Edited and extended by Robert G. Wilson v, Oct 17 2002

a(10) from Vincenzo Librandi, Oct 05 2012

a(11) from Giovanni Resta, Feb 19 2013